The invention relates generally to a snow plow assembly for mounting on a vehicle. More particularly, the invention relates to attachment and detachment of a lift assembly to the vehicle as a single unit.
It is desirable to provide a snow plow assembly with a mechanism affording attachment and detachment to a vehicle. The vehicle owner may wish to remove the snow blade during times when the need for plowing snow arises infrequently or when the vehicle is used for purposes other than plowing snow.
Conventional detachable snow plow assemblies generally provide a mount frame for permanent attachment to a frame of the vehicle, a snow blade attached to an A-frame which, in turn, can be releasably connected to the mount frame and an actuator for raising and lowering the A-frame. The mount frame is located on the front end of the vehicle generally behind the vehicle front bumper. The A-frame and attached snow plow generally are removable from the vehicle but the actuator, usually a relatively heavy hydraulic unit, normally remains attached to the vehicle. Leaving the actuator on the vehicle, when the remainder of the snow plow assembly is removed, exposes the actuator to the elements and possible damage. The permanently mounted, relatively heavy actuator also places the front of the vehicle under additional loading and can reduce the operational life of the vehicle suspension. Leaving the actuator on the vehicle also reduces fuel efficiency of the vehicle.
When plowing snow, it sometimes is desirable to push the snow into a pile. The A-frame of the snow plow assembly must be free to pivot upwardly relative to the vehicle so that the snow blade attached to the A-frame can rise up the slope of the snow pile. Another problem with conventional detachable snow plow assemblies is that the mounting frame and components supported thereby are located in a position interfering with the free upward movement of the A-frame, thereby diminishing the capacity of the snow plow lift assembly to pile snow.
Another problem associated with conventional snow plow assemblies is that the attachment and detachment of the assembly to the vehicle can require lifting of the A-frame and connection of various elements of the snow plow assembly to a mount frame. Such lifting, attachment and detachment of the snow plow assembly can be cumbersome and difficult.
Patent application Ser. No. 07/686,123; incorporated herein by reference, discloses a snow plow assembly overcoming most of the aforesaid problems. The snow plow assembly, including an actuator, is releasably disconnected from a vehicle mount frame as a single unit with the mount frame remaining connected to the vehicle. None of the mount frame extends forward of the vehicle bumper. Nevertheless, a disadvantage associated with having the mount frame attached to the underside of the vehicle at a position behind the vehicle bumper is one of poor operator visibility when mounting the snow plow assembly to the vehicle. With the snow plow assembly supported on the ground surface, the operator maneuvers the vehicle until it appears the vehicle mount frame is aligned with a mounting clevis on the lift assembly. The operator then drives the vehicle forward until the mount frame engages the mounting clevis. Unless an assistant operator is available, the operator then must get out of the vehicle and visually check to determine if the mount frame and mounting clevis are aligned. If not, the operator continues maneuvering the vehicle until alignment occurs.
Accordingly, there remains a need to provide a snow plow lift assembly allowing removal of all structural elements forward of the vehicle bumper as a single unit when the lift assembly is detached from the vehicle but provides easy alignment by a single operator when being attached to the vehicle. There also remains a need to provide a snow plow lift assembly which requires neither manual lifting when being attached or detached from the vehicle nor a heavy lift frame. There further remains a need to provide a snow plow lift assembly which allows easy access to all mechanisms requiring manual operation and has no removable parts.